Precision Electroweak Measurements on the Z Presonance

PDF Version Also Available for Download.

Description

The authors report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. the data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarized beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarized asymmetries. The mass and width of the Z boson, m{sub Z} and {Lambda}{sub Z}, and its couplings to fermions, for example the {rho} parameter and the effective electroweak mixing angle for ... continued below

Physical Description

302 pages

Creation Information

Aleph,Delphi,L3,Opal,SLD , Collaborations September 8, 2005.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

The authors report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. the data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarized beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarized asymmetries. The mass and width of the Z boson, m{sub Z} and {Lambda}{sub Z}, and its couplings to fermions, for example the {rho} parameter and the effective electroweak mixing angle for leptons, are precisely measured: m{sub Z} = 91.1875 {+-} 0.0021 GeV; {Lambda}{sub Z} = 2.4952 {+-} 0.0023 GeV; {rho}{sub {ell}} = 1.0050 {+-} 0.0010; sin{sup 2} {theta}{sub eff}{sup lept} = 0.23153 {+-} 0.00016. The number of light neutrino species is determined to be 2.9840 {+-} 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model. At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its Standard Model expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m{sub t} = 173{sub -10}{sup +13} GeV, and the mass of the W boson, m{sub W} = 80.363 {+-} 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the Standard Model. Using in addition the direct measurements of m{sub t} and m{sub W}, the mass of the as yet unobserved Standard Model Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level.

Physical Description

302 pages

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: SLAC-R-774
  • Grant Number: AC02-76SF00515
  • DOI: 10.2172/878425 | External Link
  • Office of Scientific & Technical Information Report Number: 878425
  • Archival Resource Key: ark:/67531/metadc874646

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • September 8, 2005

Added to The UNT Digital Library

  • Sept. 21, 2016, 2:29 a.m.

Description Last Updated

  • Nov. 30, 2016, 5:09 p.m.

Usage Statistics

When was this report last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Aleph,Delphi,L3,Opal,SLD , Collaborations. Precision Electroweak Measurements on the Z Presonance, report, September 8, 2005; [Menlo Park, California]. (digital.library.unt.edu/ark:/67531/metadc874646/: accessed October 22, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.